class Map
{
    constructor(el){
        //保存地图对象
        this.el = el
        //记录地图属性
        this.width = 800
        this.height = 400
    }
    //创建地图
    create(){
        //设置map属性
        this.el.style.width = this.width+'px'
        this.el.style.height = this.height+'px'
        this.el.style.background = 'url(./bg.png)'
        this.el.style.border = '10px solid green'
        this.el.style.position='relative'
    }
}